In a nutshell:
*Not paying Terrence Howard to come back as Jim Rhodes/War Machine in Iron Man 2
*Rushing Jon Favreau into making Iron Man 2 (thereby, complicating/compromising his artistic vision in the process) and then turning it into a semi-infomercial for The Avengers
*Not giving Jon Favreau a raise (considering that Iron Man broke the bank) in exchange for directing The Avengers. Not that Joss Whedon is a bad choice per se, it's just that he has an unproven track record regarding box office hits.
*Firing Edward Norton from The Avengers for not being enough of a "team player".
*Not paying Terrence Howard to come back as Jim Rhodes/War Machine in Iron Man 2
*Rushing Jon Favreau into making Iron Man 2 (thereby, complicating/compromising his artistic vision in the process) and then turning it into a semi-infomercial for The Avengers
*Not giving Jon Favreau a raise (considering that Iron Man broke the bank) in exchange for directing The Avengers. Not that Joss Whedon is a bad choice per se, it's just that he has an unproven track record regarding box office hits.
*Firing Edward Norton from The Avengers for not being enough of a "team player".